Work begins on Naples seawalls

LONG BEACH – The 109-year-old Naples seawall is currently undergoing construction as part of the first stage of a multi-phase replacement. Work began the week of Nov. 17.

The city of Long Beach announced that construction is occurring to the seawall along the Rivo Alto Canal in Naples Island. The section stretches from the Ravenna Bridge to the eastern portion of the Toledo Bridge, which spans approximately 1,900 linear feet.

“The repairs in this portion of Rivo Alto Canal are imperative to maintaining the integrity of the island, which is an asset the city aims to preserve and enhance for future generations,” said city of Long Beach Mayor Robert Garcia. “This investment preserves a beautiful area of our city that provides aquatic recreation in the canal as well as a wonderful right-of-way for the public to enjoy as pedestrian space.”

The new seawalls will consist of stainless steel sheet piles coated to prevent rust. The 47 ½ foot sheet piles will be driven into the ground using silent piler technology, which also limits vibration and liquefaction, according to the city.

Included in the six-phase project is the installation of accessible and code-compliant sidewalks, stairs for accessing gangways, ladders that lead to private slips, a new guardrail, and a new storm drain.

“This project is truly a feat of modern engineering,” said city of Long Beach Councilmember Suzie Price. “The city has been working diligently alongside residents to bring this project to fruition. I am very pleased to see construction beginning to preserve and enhance this unique part of Long Beach.”

Phase one, budgeted at $9 million, is being financed with Tidelands Operations Funds, and has a completion date of June 2015. During construction, the sidewalks on this portion will be closed to the public. Visitors can complete a full circle of the island by passing through the alleyways. Other sidewalks on the island will not be impacted. The waterway will remain open until December 15, allowing the annual boat parade to pass through. Afterward, the canal will close to all motorized vessels with the exception of boats owned by canal residents.

In 2009, an engineering study determined that some portions of the seawalls have “significant risk of ‘global’ failure due to their present deteriorated condition, if the site experiences a ‘moderate’ near-source earthquake.” The study divided the public seawalls into six phases, with the first phase addressing the areas that are in the most severe condition.

The Rivo Alto and Naples Canals were constructed in the early 1900s in the delta of the San Gabriel River, which is the area that is now Alamitos Bay. The existing vertical concrete seawalls were built in the late 1930s after the Long Beach earthquake in 1933. Subsequent repairs were made in the late 1960’s, according to the city.